The invention relates to a spring device, particularly to a spring device having a coil spring comprising an adjusting facility, as well as to an application of a spring device having an adjusting facility for the spring suspension of a vehicle, especially for the spring suspension of a motor vehicle or a bicycle.
Spring devices are employed, for example, in vehicles such as bicycles or motor vehicles, or in machines, particularly in order to improve their dynamic characteristics or to adapt them to dynamics, respectively. In so doing, various components are connected by means of spring elements for an at least partial mechanical isolation. In addition, absorber elements may be provided which influence the dynamic behavior of the overall system, and in particular prevent the overall system from over vibration.
Spring devices are employed, for example, in order to mechanically isolate the wheels of vehicles relative to the vehicle body. Spring devices are used, for example, for the wheel suspension of motor vehicles. Spring elements are also usedxe2x80x94often in combination with absorber elementsxe2x80x94in the wheel suspension of two-wheeled vehicles, especially bicycles. Spring elements are thus disposed in so-called spring forks.
For example, spring devices are disposed inside each fork cross bar which work in concert with an elastomer shock absorber. The fork cross bar is thus mechanically isolated from the stem tube by means of this spring absorbing arrangement.
Without limitation to the invention, the invention will now be described in greater detail in the following, in particular with respect to the example of a bicycle Wheel suspension, whereby it should be noted that a spring device according to the invention is likewise preferable in various other possible applications, for example in machines such as machine tools, in motor vehicle wheel suspensions and other similar contrivances.
In accordance with the present invention, a spring device is proposed having a spring, a load transmission means, as well as an adjusting means at least partially encompassed by said load transmission means, said adjusting means being provided for adjusting the position of at least one load transmission section.
The spring is disposed with load transmission sections which are encompassed by the spring surface, and within which external forces may be introduced in at least two positions respectively from at least one embracing member, said embracing members preferably being mechanically isolated by means of the spring.
Reference to load transmission sections must be hereby particularly understood as areas of the spring surface. Thus, the load transmission sections may be, dependent upon predetermined conditions, disposed at various positions on the spring surface, or at various spring surface areas, respectively. The external forces in each case are thus introduced in particular by at least one embracing member.
The term xe2x80x9cembracing memberxe2x80x9d is hereby to be understood in a broad sense. An embracing member in this case is especially a component coupled with the spring device, said component in contact with the spring device such that forces applied to the spring device by said embracing member are at least partially isolated. For example, an embracing member may be understood as a cap placed on the spring, or an absorber device adjoined to the spring, or a fork cross bar of a bicycle, or a stem tube, or any such component being in each case solidly affixed thereto.
The external forces which are introduced may be of the most diverse kinds. For example, in a corresponding application of a spring device according to the present invention, which, for example, is mounted in a fork cross bar or in a stem tube of a bicycle, or which is mounted in a corresponding manner on a bicycle rear wheel for the purpose of its suspension and which receives said induced forces from the wheel via the rider and/or from the rider alone on the one hand and, on the other hand, also those forces thereby coupled with the spring which are introduced thereupon from the ground via the bicycle wheel. Thereby, the spring device may at least partially isolate dynamic loads, in particular such as those induced by, for example, changing ground surface conditions such as rocks, curbs, pot holes and other similar environmental conditions, so that they are not transmitted on to the rider.
The adjusting means is configured such that, for example, one of the spring ends is solidly mounted in a cap-like element such as a rotating knob, whereby the cap with the spring is rotatably mounted about the spring axis. At a second position, the spring is positioned with its coils in a thread, which is disposed, for example, on the casing of an absorber cover or the like. A turning of the rotating knob induces the coils of the spring to rotate helically in the thread, the thread of the absorber cover for example, so that the thread displaces relative to the spring. Hereby, the distance between the spring end disposed with the rotating knob and the section of the spring coils presently lodged in said thread, changes, so that the springxe2x80x94without being additionally stressed or relaxedxe2x80x94changes its effective length, hence, the length between two points of contact changes. Hereby, an embracing member, which is solidly connected to the thread, is mechanically isolated from an embracing member which is solidly coupledxe2x80x94at least in the spring axis directionxe2x80x94to the cap.
According to another exemplary embodiment of the invention, a rotatably mounted bicycle seat tube has a female thread disposed in its lower section or, respectively, is solidly connected with a component such as a sleeve having a female thread. Said female thread is capable of receiving a coil spring, so that the coil spring forms a screwed-type of connection with the female thread. The coil spring is supported at one end against a fork cross bar which is mounted axially displaceable relative to the seat tube, or against another component being solidly connected thereto. Preferably, a rotary lock which is disposed between said fork cross bar and spring, or which is formed by said components respectively, prevents the end section of the spring from rotating relative to the fork cross bar. A rotation of the seat tube causes the spring, which represents a type of male thread, to move within the female thread of the seat tube so that the effective spring length changes, meaning a change is effected in the length between the coil section of the spring which is received in the female thread of the seat tube and the point of support of the spring on the fork cross bar. In this way, the effective spring length may be changed without thereby changing the initial spring tension in the effective spring length section.
According to another preferred embodiment of the present invention, which likewise may be employed for example on a bicycle, a setting knob is connected with a type of shaft having a male thread.
It is further preferred that instead of a shaft having a male thread, a type of tube comprising a female thread is provided. A combination of these two possibilities is equally preferred as well.
Said thread or said threads engage/s in the coils of the spring so that the spring forms a type of counter-thread. The spring end distal the rotating knob is supported on an embracing member such as, for example, a fork cross bar and is preferably secured at this position against rotation relative the embracing part. For example, the rotating knob including shaft, hollow shaft respectively, is inserted into the fork cross bar. Upon turning of the rotating knob, said knob including shaft retracts relative to the fork cross bar or, respectively, draws nearer thereto. Thereby, the thread connected with the setting knob screws further into the spring or, respectively, rotates out therefrom. The free end of the spring supported against the embracing part, such as the fork cross bar, elongates so that the effective spring length changes. Since the fork cross bar is disposed axially displaceable relative to the setting knob, a change of spring tension in the section of the respective effective spring length as conditional upon an adjustment operation is avoided.
In accordance with a particularly preferred embodiment of the present invention, elements are solidly coupled with the spring coils over at least one part of the spring axis. Said elements may be brought into contact with a receiving means of the embracing part. Upon a relative displacement of the embracing part with respect to the spring, other elements, or elements which are situated at another location in spring axial direction, are brought to said receiving means and may be hooked or similarly fastened thereupon.
The invention is particularly advantageous insofar as it enables an adjustment of the characteristic curve of the springxe2x80x94in particular, an infinitely variable adjustmentxe2x80x94without thereby changing the adjustment of the spring initial tension.
According to a particularly preferred embodiment of the invention, the adjusting means which, for example is designed as a rotating knob disposed with a tube shaft having a female thread, or as a rotating knob disposed with a tube shaft having a male thread, is capable of adjusting the spacing of the load transmission sections on the spring while the spring tension remains constant.
According to a particularly preferred embodiment of the present invention, the spring is configured as a coil spring.
According to a further preferred embodiment of the invention, the load transmission means and/or the adjusting means extend/s at least partially into the inner section of the coils or, respectively, into the area which the coils span. Since the coils are helically formed, they define a kind of tubular region.
It should be noted that the term xe2x80x9ctubular regionxe2x80x9d must be understood in a broad sense. For example, the present invention also encompasses coils defining a kind of truncated conical region.
It is preferred that the load transmission means and/or the adjusting means extend/s at least partially into the inner section of said tubular region, whereby sections of the load transmission means, adjusting means respectively, extend to the spring, said sections engaging into the spring. It is further preferred that sections extend from the spring to the load transmission, adjusting means respectively, which engage into said load transmission means or adjusting means, respectively. The position at which the load transmission means, adjusting means respectively, couples with the coils of the spring, is preferably adjustable in the axial direction of the spring.
It is further preferred that the load transmission means, adjusting means respectively, externally enclose the coils, tubular region respectively, whereby sections of the load transmission means or the adjusting means, respectively, extend inwardly to the coils, said sections being coupled with the coils. Also here, the inverse is such preferred that sections extend from the coils to the load transmission means, adjusting means respectively, and which are then coupled at this point to said load transmission means or adjusting means, respectively. Here also, it is preferred that the position said coupling areas is adjustable in the axial direction of the spring.
According to a particularly preferred embodiment of the present invention, the coupling areas are configured such that a solid, immovable connection is or may be established between the load transmission means, adjusting means respectively, and the spring in the coupling region.
It is further preferred that the connection in the coupling area is one having play or one which has at least a degree of flexibility, whereby a relative movement between the spring and the adjusting means, load transmission means respectively, is hindered by means of an additional locking mechanism. Said locking mechanism, for example, is configured such that the spring is screwed around a load transmission means which, for example, is of helical shape, and a degree of flexibility fundamentally exists in the direction of the thread pitch. A relative movement may be prevented, for example, by locking the helical component, hence the load transmission means, at another position, for example by means of a catching detent mechanism. Thus, the screw is not capable of exerting a relative rotation with respect to the spring. A relative axial movement between the screw and the spring is prevented by the spring""s engagement into the screw""s thread.
It is further preferred that the screw-type connection is of a self-locking configuration.
According to a preferred embodiment of the present invention, the area the load transmission or adjusting means extending radially outwardly and/or radially inwardly of the spring coils, engages in at least one coil interspace. Upon a force being applied to the spring from this engaging area and/or a second area disposed, for example, on the other spring end, the spring is braced with its coils against said force in said area engaging the coils, so that an isolating of the embracing parts is effected.
It is further preferred that the afore-mentioned area engages in various coil interspaces. It is particularly preferred that it engages in adjacent coil interspaces in axial direction, whereby said engaging area comprises a connective region in the form of a recess which embraces said engaged coil. This is realized, for example, in that a thread is screwed into the spring coils.
A thread of this kind connected with the load transmission means, adjusting means respectively, is preferably so dimensioned and disposed relative to the spring such that, depending upon the adjustment position, the length of the thread engaging in the spring varies.
In accordance with a particularly preferred embodiment of the present invention, the length of the thread engaging in the spring is always constant, whereby solely its displacement in axial direction relative to the spring occurs during a change in adjustment.
According to a particularly preferred embodiment of the present invention, at least one part of the adjusting means and/or the load transmission means moves at least occasionally along a three-dimensional path during adjustment. This is realized, for example, in that the load transmission means comprises a thread which engages in the spring and then displaces relative to the spring upon adjustment or change of the adjustment. The external areas of the thread thereby run on a spiral-shaped, hence three-dimensional course.
It is further preferred that at least one part of the adjusting means and/or the load transmission means moves at least occasionally along a two-dimensional, e.g. linear, path during adjustment. This is realized, for example, in that a component is provided which is displaceable in the spring axial direction, such as a kind of bar comprising tongues or similar components, which are capable of being displaced in radial direction from the bar towards the threads or thread interspaces, respectively. In operation, said tongues or similar components engage in the interspaces, around the screw pitches, respectively. In order to change adjustment, a mechanism moves them out of their engaging position in the direction of the bar. Subsequently, the bar is displaced in axial direction until the desired position is reached. Then the tongues or similar components are moved back into their engaging position. The establishing and releasing of the engaging position may be realized in such a manner that, for example, the tongues or the like are spring-loaded and are then urged into engaging position by means of the spring action. Via a cable mechanism, a rod mechanism, or the like, they may be activatedxe2x80x94for example, by pulling on the cablexe2x80x94out of the engaging position relative to the spring tension. Subsequent to relieving the force on the cable or rod, they snap back into their engaging position.
According to a particularly preferred embodiment of the present invention, the spring device comprises a locking means for fixing a predetermined relative position between the load transmission means, the adjusting means respectively, and the spring. As mentioned above, this is realized, for example, in that the load transmission means, adjusting means respectively, comprises a thread for engaging in the screw, whereby the locking may be established in that a rotation of the load transmission means, adjusting means respectively, may be blockedxe2x80x94for example, via a spring-loaded snap-lock mechanism.
According to a particularly preferred embodiment of the present invention, the spring device comprises a compensating mechanism or, respectively, the spring device or the load transmission means or the adjusting means is coupled with a compensating mechanism. The load transmission means, for example, is configured as a helically-shaped element as already described above. Thus, during adjustment, the load transmission, adjusting means respectively, moves in axial direction relative to the spring so that the spacing between the distal end of the load transmission means from the spring, and that between the distal spring end from the load transmission means, changes. At these positions, for example, force is received by further embracing components. Therefore, it may be desirable that the spacing between these points remains constant also during adjustment of the spring. To this purpose, the load transmission means is provided with, for example, a second thread, which engages in the thread of a sleeve. Said sleeve is fixed. Provided that the spacing between the two afore-mentioned ends of the spring, load transmission means respectively, now changes, the load transmission means simultaneously displaces relative to the sleeve. If, for example, the spacing between the above-mentioned points is shortened, then the spacing between the sleeve distal end from the spring and the distal end of the load transmission means from the sleeve will simultaneously lengthen. Said two dimensions are preferably identical so that the spacing between the sleeve distal end from the spring and the distal spring end from the sleeve remains constant.
According to a particularly preferred embodiment of the present invention, a compensating mechanism of this kind is not provided.
This is preferred when, for example, in addition to a change of the characteristic curve line, also a change of spacing in the load transmission region is desired as well. Thus, for example, it may be desired that during an uphill bicycle ride, a spring deflection of 60 mm at a steep angle of lock and a tighter calibrated spring is desired, whereas during a downhill ride, a spring deflection of 120 mm at a flat angle of lock and at slacker calibration is desired.
Another example for a spring device where besides a change of the characteristic curve line, a change in the afore-mentioned clearance spacings is also desired, is represented by an infinitely variable seat height adjuster for a motorcycle Hereby, it may be desired that while riding off-road, or riding over any kind of uneven ground, a high seat height with slacker suspension is desired, whereas while riding over even ground or in sporting events, a low seat height with tighter spring calibration is desired.
Another illustration of an example in which besides a changed characteristic curve line, a changed clearance spacing is also desired, is represented by an automobile""s infinitely variable level control. When driving over city streets, for example, having a high ground clearance and a comfortable calibration may be desired. On the highway, however, a lower ground clearance at tighter spring calibration may be desired.
The combination of spring calibration and clearance spacing is also advantageous for optimizing a chassis and for regulating the center of gravity in racing situations.
These various different combinations of height adjustment and change in characteristic curve may be realized by the use of a spring device according to the present invention.
According to a particularly preferred embodiment of the present invention, the spring device is coupled with an absorber device or, respectively, the spring device comprises an absorber device or, respectively, the spring device is configured in combination with an absorber device. The absorber device may be, for example, a component of the load transmission means and/or the adjusting means.
It is preferred that the absorber device is gang-switched in parallel with the spring device. It is particularly preferred that the spring device is in series connection with the absorber device.
According to a particularly preferred embodiment of the present invention, various load transmission sections are adjustable on the spring, in the manner of adjustment as described above. It is preferred that, for example, two load transmission sections are provided on a spring, with the spring having a different spring constant along its axis. For example, two springs of different rigidity are each interconnected at one each of their respective ends, whereby a load transmission means with an adjusting means engages in each of said springs respectively. Thus, the two load transmission sections may be adjusted independently from one another. Hereby, it can be additionally beneficial to utilize springs having different rigidity. For example, this enables attaining a change in the load transmission section and the spring rigidity while the clearance spacing remaining constant.
Preferably, a spring device in accordance with the present invention is utilized for the suspension of a vehicle such as a motor vehicle or a bicycle or a motorcycle, etc. The application of a spring device in accordance with the present invention is also preferred in (industrial) machines such as machine tools.
It should be pointed out that the interaction of the various characteristics according to the present invention is preferred in any combination desired. In particular, combinations of characteristics as disclosed by the independent claims are preferred in any and all cases, even should one or more characteristics be omitted. A combination of procedures according to the present invention is also preferred.
It should be noted that upon linking of characteristics with xe2x80x9cor,xe2x80x9d in each case said xe2x80x9corxe2x80x9d is to be understood as a mathematical xe2x80x9corxe2x80x9d on the one hand, and as an xe2x80x9corxe2x80x9d excluding the respective other possibility on the other hand.
Further, reference should be made to the fact that the term xe2x80x9ccontrol,xe2x80x9d in the sense of the invention, as well as all terms derived therefrom, must be understood in a broad sense. In particular, it encompasses a regulating and/or control corresponding to the German Industrial Standards (DIN).
It is obvious to the expert skilled in the art that in addition to the embodiment herein described, the invention comprises a plurality of further conceivable modifications and realizations. Particularly, the invention is not limited to the embodiments described herein.